Chinda Sutiwanich, Thanu Hanpattanapanich, Santi Pailoplee, and Punya Charusiri

pp. 453 - 466

Abstract

Seismic hazard maps of southern Thailand were obtained from the integration of crustal fault, areal and subduction
source models using probability seismic hazard analysis and the application of a logic tree approach. The hazard maps show
the mean peak ground and spectral accelerations at 0.2, 0.3 and 1.0 second periods with a 10%, 5%, 2% and 0.5% probability
of exceedance in 50-year hazard levels. The highest hazard areas were revealed to be in the Muang, Phanom, and Viphavadi
districts of Surat Thani province, the Thap Put district of Phang Nga province, and the Plai Phraya district of Krabi province.
The lowest hazard areas are in the southernmost part of Thailand e.g. Yala, Pattani and Narathiwat provinces. The maximum
values of the mean peak ground acceleration for the 475–9,975 yr return period are 0.28-0.52 g and the maximum spectral
accelerations at 0.2 seconds for the same return period are 0.52-0.80 g. Similar hazard is also obtained for different return
periods. Presented seismic hazard maps are useful as a guideline for the future design of buildings, bridges or dams, for rock
sites to resist earthquake forces.